1. Blend 1 banana with the milk, cinnamon, and sweetener. Spread nut butter on 1-2 pieces bread.
2. Slice remaining banana and place it between bread slices. If your bread is soft, you can pinch the edges together a bit to seal it, but it's not necessary.
3. Coat both sides of bread with milk/banana mixture. Cook over medium-high heat until brown, around 5 minutes per side.
This sandwich is beautiful and filling. Try putting vegan chocolate chips or carob chips in it, or use sunflower seed butter instead of nut butter. Try putting in whatever your little heart desires, 'cos hey, it's your French toast!
Source of recipe: Inspired by Carrots n Cake's almond butter stuffed French toast. The recipe wasn't vegan, so I tweaked it and added some stuff. http://carrotsncake.com/2009/01/almond-butter-stuffed-french-toast.html